Blue Laser for Polymerization of Bulk Fill Composites: Influence on dentin bond strength and temperature rise during curing and co-curing method.

Blue diode lasers are alternative curing devices for dental composites. The aim of this study was to investigate the influence of blue diode laser polymerization on shear bond strength of bulk fill composites to human dentin and temperature rise during two types of polymerization. Composite cylinders of SDR Plus(SDR) and Ever X Flow(EX) were bonded to dentin slabs using Adhese Universal and curing devices blue diode laser (449 nm, 1.6 W) and Power Cure LED. For each material and curing device there were two polymerization approaches: 1)conventional: separate curing of adhesive; 2)co-curing: simultaneous adhesive and composite curing. Polymerization modes for each material in conventional and co-curing(c) approach were: blue laser 2000 mW/cm2 for 5 s (L5 and L5c); blue laser 1000 mW/cm2 for 10 s (L10 and L10c); Power Cure 2000 mW/cm2 for 5 s (LED5 and LED5c); Power Cure 1000 mW/cm2 for 10 s (LED10 and LED10c). Temeperature was measured using thermal vision camera. For SDR, the highest bond strength was 24.3 MPa in L10c, and the lowest 9.2 MPa in LED5c. EX exhibited the highest bond strength(21.3 MPa) in LED5, and the lowest in L5(7.7 MPa). The highest temperature rise for SDR was in L10 and L5 (7.3 and 7.2 °C), and the lowest in LED5(0.8 °C). For EX, the highest temperature rise was in L5 (13.0 °C), and the lowest in LED5 (0.7 °C). Temperature rise was higher during blue laser polymerization, especially at high intensity and with conventional curing. Preferable blue laser curing mode is co-curing at 1000mW/cm2 for 10 s.

Clinical performance of a glass-hybrid system in comparison with a resin composite in two-surface class II restorations: a 5-year randomised multi-centre study.

OBJECTIVE: To evaluate the 5-year clinical performance of a glass hybrid restorative system and a nano-hybrid resin composite in moderate to large two-surface class II cavities. MATERIALS AND METHODS: This study was carried out by dental schools in Zagreb, Croatia; Izmir, Turkey; Belgrade, Serbia; and Milan, Italy. A total of 180 patients requiring two class-II two-surface restorations in the molars of the same jaw were recruited. The teeth were randomly restored with either a nano-hybrid resin composite (Tetric EvoCeram, Ivoclar Vivadent) or a glass-hybrid material (EQUIA Forte, GC). During the 5-year follow-up, two calibrated evaluators at each centre scored the restorations annually using the FDI-2 scoring system. The survival rates were calculated using the Kaplan-Meier method and compared using non-parametric matched pair tests (p < 0.05). RESULTS: There were no statistically significant differences between the overall survival and success rates of the two types of restorations (p>0.05). The success rates (FDI-2 scores 1-3) for EQUIA Forte were 81.9% (average annual failure rate: 3.9%) and 90.7% for Tetric EvoCeram (average annual failure rate: 1.9%). The survival rates (FDI-2 scores 1-4) for EQUIA Forte and Tetric EvoCeram were 94.5% and 94.4%, respectively, with an average annual failure rate of 1.1%. CONCLUSIONS: In terms of success and survival rates, both the glass-hybrid restorative system and the nano-hybrid resin composite have been shown to perform satisfactorily. CLINICAL RELEVANCE: The results of this study indicate that EQUIA Forte can be one of the therapeutic options for moderate to large two-surface class II restorations of posterior teeth.

Influence of different laser-assisted retrograde cavity preparation techniques on bond strength of bioceramic-based material to root dentine.

The purposes of the study were to evaluate the bond strength of bioceramic TotalFill root repair material (RRM) in retrograde cavities prepared using Er:YAG and Er,Cr:YSGG laser and steel bur, and to analyze failure modes. The root canals of 30 single-rooted teeth were endodontically treated, their root-ends were resected using a diamond bur, and the teeth were randomly divided into three groups (N = 10) according to the retrograde cavity preparation technique: (1) Er:YAG laser, (2) Er,Cr:YSGG laser, and (3) steel bur. All retrograde cavities were filled with the TotalFill RRM which was prepared according to the manufacturers' instructions. Push-out test was performed using universal testing machine, and failure mode was analyzed using a scanning electron microscope. The data were analyzed using one-way ANOVA, post hoc analysis with Bonferroni correction, and Fisher-Freeman-Halton exact test (p < 0.05). In the Er:YAG-, Er,Cr:YSGG-, and steel bur-prepared cavities, mean bond strengths (MPa) were 12.76, 8.44, and 6.01, respectively. The bond strength of the TotalFill RRM to dentin was significantly higher in the Er:YAG laser compared with the steel bur-prepared cavities (p = 0.004). The bond strength was not significantly different between the Er:YAG and Er,Cr:YSGG cavities (p = 0.074) and between the Er,Cr:YSGG and bur cavities (p = 0.648). In the cavities prepared by the Er,Cr:YSGG laser and bur, the failure mode of the TotalFill RRM was predominantly mixed, then adhesive and cohesive. In the Er:YAG laser-prepared cavities, the most common failure mode was adhesive, followed by mixed type and no cohesive failure. The bond strength of the TotalFill RRM to dentin was highest in the group of retrograde cavities prepared by the Er:YAG laser.

EVALUATION OF INNOVATIVE DIGITALLY CONTROLLED ER:YAG LASER IN SURGICAL TREATMENT OF ORAL LEUKOPLAKIA - A PRELIMINARY STUDY.

The use of lasers for treatment of oral leukoplakia has gained a lot of interest in the past years, however, data on the use of Er:YAG laser are scarce. The aim of this study was to compare the efficacy of Er:YAG laser and 1% topical isotretinoin in the treatment of 27 oral leukoplakia patients. Er:YAG laser (LightWalker AT, Fotona, Slovenia) was used in 27 patients with 27 leukoplakia lesions. Postoperative pain was assessed by use of visual analog scale (VAS), and the impact of laser treatment on the quality of life was assessed by the OHIP-14 questionnaire (Croatian version). Control group consisted of the same 27 patients previously treated with 1% topical isotretionin three times a day during the period of one year. No improvement in the size of leukoplakia lesions was observed after treatment with topical isotretinoin. There were significant differences between men and women according to leukoplakia localization, number of laser sessions and VAS (p<0.05). At follow-up after six months and one year, there was no recurrence of lesions. Er:YAG laser is a successful treatment for oral leukoplakia. Topical isotretionin treatment is unsuccessful in patients with oral leukoplakia.

Push-out bond strength of three different calcium silicate-based root-end filling materials after ultrasonic retrograde cavity preparation.

OBJECTIVE: The aim of this study was to evaluate the bond strength of three calcium silicate-based root-end filling materials. MATERIALS AND METHODS: The root canals of 30 single-rooted teeth were endodontically treated; their root ends were resected and root-end cavities were prepared using ultrasonic tip. The teeth were randomly divided into three groups according to the material: (1) Micro-Mega mineral trioxide aggregate (MM-MTA), (2) Biodentine, and (3) TotalFill root repair material (RRM). Push-out test was performed using universal testing machine, and failure mode was analyzed by stereomicroscope. The data were statistically analyzed using Kruskal-Wallis and Man-Whitney post hoc tests. All p values < 0.05 were considered significant. RESULTS: TotalFill RRM exhibited significantly higher bond strength (12.69 MPa) than Biodentine (9.34 MPa, p = 0.023) and MM-MTA (7.89 MPa, p = 0.002). The difference between Biodentine and MM-MTA was not significant (p = 0.447). Mixed failures were the most noted in all three groups. MM-MTA had more adhesive failures than Biodentine and TotalFill, and no cohesive failures, but without statistical significance (p = 0.591). CONCLUSION: The bond strength was the highest for TotalFill RRM. CLINICAL RELEVANCE: In order to provide a persistent apical seal, root-end filling materials should resist dislodgement under static conditions, during function and operative procedures. TotalFill RRM exhibited higher bond strength to dentin than MM-MTA and Biodentine.

In vitro retention of prefabricated and individually formed posts: A pilot study.

STATEMENT OF PROBLEM: Data on the retention of individually formed fiber-reinforced composite posts (everStick) cemented with self-adhesive cement are lacking. PURPOSE: The purpose of this in vitro study was to investigate the pull-out strength of 2 different fiber-reinforced composite posts (prefabricated and individually formed) cemented into extracted teeth with self-adhesive resin cement. MATERIAL AND METHODS: Thirty extracted single-rooted human teeth were decoronated, endodontically treated, and prepared with post spaces of equal length. Prepared specimens were divided into 2 groups (n=15 each) based on the type of post: commercially prefabricated fiber posts (GC) and individually formed resin posts (using GC reinforcing fibers). Self-adhesive resin cement (G-CEM LinkAce; GC) was used to cement all posts. Each post was held with moderate pressure, and root surfaces were light polymerized for 20 seconds (650 mW/cm2). After cementation, the specimens were stored in saline solution for 30 days. Treated teeth were kept in water for 24 hours before pull-out testing parallel to the longitudinal axis of the posts. Data were analyzed using the Student t test (α=.05) and the coefficient of variance as the ratio of the standard deviation to the mean. RESULTS: The mean pull-out retention strength was 185.7 ±61.2 N for the prefabricated fiber posts and 98.9 ±56.5 N for the individually formed fiber posts (P=.026). CONCLUSIONS: The prefabricated fiber posts exhibited significantly higher retention forces than the individually formed posts.

Effect of photon induced photoacoustic streaming (PIPS) on bond strength to dentine of two root canal filling materials.

OBJECTIVES: The aim of this study was to evaluate the effect of photon induced photoacoustic streaming (PIPS) technique in combination with EDTA on bond strength of gutta-percha/AH Plus and Resilon/RealSeal SE root canal fillings to root dentine. MATERIALS AND METHODS: Forty freshly extracted human maxillary anterior teeth with intact straight roots, were instrumented endodontically with rotating ProTaper instruments and randomly divided into two experimental groups. In group 1 (n = 20), root canals were rinsed for 1 minute with 2 ml of 17% EDTA. In group 2 (n = 20), Er:YAG laser, with a 14 mm long 400 µ diameter tapered PIPS tip, was used for 1 minute with 2 ml of 17% EDTA. The laser parameters used were: 20 mJ per pulse, 15 Hz, 50 microsecond. In each experimental group, half of the root canals (n = 10) were obturated with gutta-percha/AH Plus and other half (n = 10) with Resilon/RealSeal SE. A micropush-out test was performed on sectiond specimens of the filled roots using a universal testing machine and resistance to failure plus failure modes were determined. RESULTS: Both gutta-percha/AH Plus groups had higher bond strength to root dentin than the Resilon/RealSeal SE groups (P < 0.05). The smear layer removal protocol, with EDTA only or combining PIPS technique with EDTA, had no influence on bond strength of either gutta-percha/AH Plus, or Resilon/RealSeal SE (P > 0.05). CONCLUSION: Within the limitations of this study, it was found that the application of the PIPS technique did not have an affect on the push-out bond strength of Resilon/RealSeal SE root canal filling to dentin nor on the gutta-percha/AH Plus. A significant difference in bond strength was noted between the two root canal filling materials. Lasers Surg. Med. 48:951-954, 2016. © 2016 Wiley Periodicals, Inc.

Comparison of vertical forces during root canal filling with three different obturation techniques.

The aim of this study was to examine and compare vertical forces exerted during root canal obturation with the cold lateral condensation technique, Thermafil technique and ProTaper guttapercha. Fourty-five single-rooted permanent teeth were used in the study. All specimens were instrumented using the ProTaper rotating technique and were randomly divided into three experimental groups (n = 15 per group). In the first group, root canals were obturated using the cold lateral condensation technique. In the second group, the Thermafil technique was used to obturate root canals. In the last group, a ProTaper gutta-percha of the same taper as the instrumented root canals was used for root canal obturation. Vertical forces were measured using the device developed for simulation of endodontic treatment. The results showed a statistically significant difference (p = 0.0001) for vertical forces when cold lateral condensation obturation technique was used in comparison to other techniques. No statistically significant difference was found for vertical forces during obturation with Thermafil and ProTaper gutta-percha (p = 0.16). The cold lateral condensation technique exerted higher vertical forces in comparison to the Thermafil and ProTaper obturation techniques.

Microleakage along glass-fibre posts cemented with three different materials after cyclic loading: a pilot study.

The purpose of this in vitro study was to evaluate microleakage along glass-fibre posts cemented with three different cements after cyclic loading. After post-space preparation, fifty obturated root canals were randomly divided into three experimental groups and two control groups. In group 1, Glassix posts were cemented using Harvard cement, in group 2, Fuji PLUS cement was used and in group 3, Variolink II was used for post cementation. The specimens were artificially aged by loading in a special testing machine. Coronal leakage was evaluated using a fluid transport system. Posts cemented with Variolink II, showed significantly higher failure rate after loading, compared to group 1 and 2 (p = 0.009). Comparing microleakage in samples that have not failed, specimens cemented with Variolink II showed significantly less fluid transport than specimens cemented with zinc phosphate and glass ionomer cements (p = 0.04 and p = 0.006, respectively). Variolink II cement exibited significantly less fluid movement compared with Harvard and Fuji PLUS cement.

Efficacy of Shock Wave-Enhanced Emission Photoacoustic Streaming (SWEEPS) in the Removal of Different Combinations of Sealers Used with Two Obturation Techniques: A Micro-CT Study.

This study sought to evaluate the efficacy of SWEEPS in the removal of epoxy-resin-based and calcium-silicate-containing endodontic sealer combined with single-cone and carrier-based obturation techniques through a micro-CT analysis. Seventy-six single-rooted extracted human teeth with single root canal were instrumented with Reciproc instruments. Specimens were randomly divided into four groups (n = 19) according to the root canal filling material and obturation technique: (1) AH Plus sealer + Reciproc gutta-percha, (2) TotalFill BC sealer + TotalFill BC Points, (3) AH Plus sealer + Guttafusion obturator, and (4) MTA Fillapex + Guttafusion obturator. All specimens were re-treated one week later using Reciproc instruments. Following re-treatment, root canals were additionally irrigated using the Auto SWEEPS modality. The differences in the root canal filling remnants were analyzed by micro-CT scanning of each tooth after root canal obturation, after re-treatment, and after additional SWEEPS treatment. Statistical analysis was performed using an analysis of variance (p < 0.05). The additional treatment with SWEEPS significantly reduced the volume of the root canal filling materials in all experimental groups compared to the removal of root canal filling using only reciprocating instruments (p < 0.05). However, the root canal filling was not removed completely from any of the samples. SWEEPS can be used to enhance the removal of both epoxy-resin-based and calcium-silicate-containing sealers, in combination with single-cone and carrier-based obturation techniques.

Restorative treatment decisions of Croatian university teachers.

This study aimed to identify differences in diagnostic criteria and restorative treatment among Croatian university teachers. The questionnaire was distributed to 120 Croatian university teachers in Zagreb and Rijeka. Responses were collected from 59 (49.2%) university teachers. Treatment thresholds for hypothetical approximal and occlusal caries, as well as most favored types of restorative techniques and materials were assessed. The majority (34%) of the respondents would intervene for an approximal caries lesion at the enamel-dentin junction. The leading strategy for occlusal caries was postponing operative treatment until the caries lesion was in the outer third of dentin and removing caries tissue only. Composite resin was the predominant material of choice for restoration of approximal and occlusal caries (70% and 81% respectively). More than half (54%) of Croatian university teachers believed the radiographs underestimated the depth of the caries lesion compared with clinical finding. Findings of this study should be a guideline for Croatian university teachers for a more consistent and modern teaching on the subject of caries management.

Distribution of RoekoSeal sealer applied by three obturation techniques.

The aim of the study was to evaluate the distribution of Roekoseal Automix sealer using three different obturation techniques. Forty-five single-rooted extracted human teeth were prepared in a crown-down manner using ProFile instruments. After instrumentation the specimens were filled using Roekoseal Automix with the cold lateral condensation, Thermafil and Obtura II techniques. Each root was sectioned horizontally. Color images were obtained using a reflected-light microscope. The cross-sections were assessed by microscopy for distribution of the sealer. Root canals filled with cold lateral condensation technique had statistically significant (p = 0.0001) more sealer in the apical portion in comparison to the apical portion of the specimens obturated with Thermafil and Obtura II techniques.

Microtensile Bond Strength of Fiber-Reinforced and Particulate Filler Composite to Coronal and Pulp Chamber Floor Dentin.

This ex vivo study aimed to compare the microtensile bond strength of fiber-reinforced and particulate filler composite to coronal and pulp chamber floor dentin using a self-etching adhesive system. Coronal dentin of 40 human molar teeth was exposed by cutting occlusal enamel with a low-speed saw. Teeth were then randomly divided into two groups (n = 20). The first group was left as is, while in the second group, pulp chamber floor dentin was exposed by trepanation. After placement of a self-etching adhesive system (G-aenial Bond, GC, Tokyo, Japan), groups were further divided into two sub-groups (n = 10) according to the type of composite: fiber-reinforced composite (EP, everX Posterior, GC, Tokyo, Japan) and particulate filler composite (GP, G-aenial Posterior, GC, Tokyo, Japan). Then, composite blocks were built up. Sticks (1.0 × 1.0 mm2) were obtained from each specimen by sectioning, then microtensile bond strength (µTBS) test was performed. Statistical analysis included one-way ANOVA test and Student's t-test (p < 0.05). µTBS values were 22.91 ± 14.66 and 24.44 ± 13.72 MPa on coronal dentin, 14.00 ± 5.83 and 12.10 ± 8.89 MPa on pulp chamber floor dentin for EP and GP, respectively. Coronal dentin yielded significantly higher µTBS than pulp chamber floor dentin (p < 0.05), independently from the tested composites.

Efficacy of Reciprocating Instruments in the Removal of Bioceramic and Epoxy Resin-Based Sealers: Micro-CT Analysis.

The objective of this study was to evaluate the efficacy of reciprocating instruments in the removal of bioceramic and epoxy resin-based sealers using micro-CT analysis. Root canals of 40 extracted human teeth were instrumented with a size R25 Reciproc instrument. Specimens were randomly divided into two groups (n = 20) according to the root canal filling material. In the first group, root canals were obturated with AH Plus sealer and Reciproc R25 gutta-percha. In the second group, a combination of bioceramic gutta-percha (TotalFill BC) and bioceramic sealer (TotalFill BC) was used. After one week, the retreatment of all specimens was performed using Reciproc instruments. To analyze the differences in the filling remnants, specimens were scanned in a micro-CT device after obturation and after the retreatment procedure. Statistical analysis was performed using the Mann-Whitney U test (p < 0.05). A combination of bioceramic sealer and bioceramic gutta-percha was more effectively removed from canals using a reciprocating instrument, with a filling remnants volume of 4.01 ± 3.13 mm3, in comparison to the combination of epoxy resin-based sealer and gutta-percha (6.96 ± 2.70 mm3) (p < 0.05). A reciprocating instrument was more effective in removing bioceramic sealers than epoxy resin-based sealers, although none of the root canal filling materials were completely removed from the root canals.

Compressive Strength of Conventional Glass Ionomer Cement Modified with TiO2 Nano-Powder and Marine-Derived HAp Micro-Powder.

The aim of this research was to investigate the compressive strength (CS), breaking strength (BS), and compressive modulus (CM) of conventional glass ionomer cement (GIC) modified with TiO2 nano particles, marine-derived hydroxyapatite (md-HAp) microparticles (<45 µm), and a combination of TiO2 NP and md-HAp particles. The materials used in the study were conventional GIC Fuji IX GP Extra (GC Corporation, Tokyo, Japan), TiO2 powder P25 (Degussa, Essen, Germany), and HAp synthesized from cuttlefish bone and ground in a mortar to obtain md-HAp powder. md-HAp was characterized using FTIR and SEM analysis. There were four groups of GIC samples: (i) Fuji IX control group, (ii) powder modified with 3 wt% TiO2, (iii) powder modified with 3 wt% HAp, and (iv) powder modified with 1.5 wt% TiO2 + 1.5 wt% HAp. Measurements were performed in a universal testing machine, and CS, BS, and CM were calculated. Statistical analysis was performed using ANOVA and Tukey's tests. CS, BS, and CM differed significantly between the Fuji IX control group and all experimental groups while differences between the experimental groups were not statistically significant. The addition of TiO2 NP, md-HAp micro-sized particles, and a combination of TiO2 and md-HAp reduced the CS, BS, and CM of conventional GICs when mixed at the powder/liquid (p/l) ratio recommended by the manufacturer.

Survey of Croatian dentists' restorative treatment decisions on approximal caries lesions.

AIM: To assess Croatian dentists' restorative treatment decisions on approximal caries lesions, including treatment threshold and restorative methods and materials. METHODS: Croatian translation of the questionnaire assessing restorative treatment decisions on approximal caries, previously validated and used in Norway and Sweden, was distributed to a random sample (n=800) of Croatian dentists. A total of 307 (38%) dentists answered the questionnaire. The assessed variables were treatment threshold for hypothetical approximal caries lesion and the most favored types of restorative techniques and materials. RESULTS: A third of the respondents (39%, 95% confidence interval [CI], 34-44%) would intervene for an approximal caries lesion at the dentin-enamel junction, but a larger proportion (42%; 95% CI, 36-48%) would treat a caries lesion confined to the enamel. For restoration of approximal caries, the majority (66%; 95% CI, 61-71%) would use composite resin. CONCLUSION: Croatian dentists tend to restore approximal caries lesions when the lesions are confined to the enamel and their development can still be arrested.

Clinical Performance of a Glass-Hybrid System Compared with a Resin Composite in the Posterior Region: Results of a 2-year Multicenter Study.

PURPOSE: To compare the clinical performance of a glass hybrid restorative system, EQUIA Forte, with that of a nanohybrid resin composite, Tetric EvoCeram, in two-surface class II cavities. MATERIALS AND METHODS: This multicenter, randomized controlled clinical study was conducted at four different dental schools. In total, 360 restorations were placed in patients in need of two class-II, two-surface restorations in the molar region of the same jaw. Each patient received one glass hybrid restoration (EQUIA Forte, GC) and one resin composite restoration (Tetric EvoCeram, Ivoclar Vivadent). Two independent evaluators performed a clinical evaluation of each site after 1 week (baseline), 1 year, and 2 years using the criteria of the FDI World Dental Federation (FDI-2). RESULTS: The estimated survival rates at the 2-year recall were 93.6% and 94.5% for EQUIA Forte and Tetric EvoCeram, respectively. There were no significant differences in the survival rates or in any of the evaluated esthetic, functional or biological properties between EQUIA Forte and Tetric EvoCeram restorations (p ˃ 0.05). CONCLUSION: Both the glass-hybrid restorative system and nanohybrid resin composite showed good clinical performance in moderate to large two-surface class II restorations in a 2-year follow-up.

Bond Strength of Individually Formed and Prefabricated Fiber-reinforced Composite Posts.

PURPOSE: To investigate the micro push-out bond strength of individually formed (everStick Post) and prefabricated (GC Fiber Post) fiber-reinforced composite (FRC) posts cemented with three different types of self-adhesive composite cements. MATERIALS AND METHODS: Forty-two single-rooted human teeth were decoronated, endodontically treated, and had post spaces prepared for everStick Post (n = 21) or GC Fiber Post (n = 21). The teeth were randomly divided into three subgroups (n = 7), and posts were cemented either with G-CEM LinkAce (GC), SpeedCEM (Ivoclar Vivadent) or RelyX U200 (3M Oral Care). Specimens were then perpendicularly sectioned and divided at the cementoenamel junction into two root levels: coronal or apical. A micro push-out test was performed using an 0.8-mm-wide stainless steel plunger. Bond strength was calculated in MPa by dividing the fracture load (N) by the bonded surface area (mm2). Log-transformed data was statistically analyzed using factorial ANOVA and Tukey's post-hoc test (α < 0.05). Fracture modes were determined employing a stereomicroscope, and differences were evaluated using a likelihood ratio test and Pearson's chi-squared test. Specimens were also observed using SEM. RESULTS: Bond strengths were significantly affected by both post type and root level (p < 0.05), but not by self-adhesive cement (p > 0.05). Fracture types showed a significantly higher prevalence of adhesive fractures at the apical level, with all fractures starting at the cement-dentin interface. CONCLUSION: Individually formed FRC posts demonstrated greater bond strength than their prefabricated FRC counterparts. The apical level of the luted posts yielded lower bond strengths than the coronal level. Failures were predominantly adhesive at the cement-dentin interface.

Substituting dietary polyunsaturated fat with monounsaturated fat increases insulin sensitivity in cultured rat hepatocytes.

Increased dietary fat intake generally, and saturated fat specifically, will lead to impairment of insulin action and to development of metabolic syndrome. The aim of this study was to find out changing of hepatic glucose output in dependence of high monounsaturated and high polyunsaturated fat diet and possible direct action of insulin in hepatocytes. Hepatocytes were isolated by a collagenase perfusion technique and cultured for 24 h in M 199 serum-free medium. The glucose production in hepatocytes isolated from rats on high polyunsaturated fat diet, as well as those isolated from rats on high monounsaturated fat diet was significantly higher than in standard controls. Insulin significantly decreased glucose production but only in hepatocytes obtained from rats on high monounsaturated fat diet. On the other side energy expenditure was significantly higher in rats on high monounsaturated fat diet and significantly lower in rats on high polyunsaturated fat diet comparable with animals on standard diet. Monounsaturated fat in Mediterranean diet could have beneficial effect on the development of the metabolic syndrome by increasing insulin sensitivity and energy expenditure.

Cytotoxicity and Genotoxicity of Resin Based Dental Materials in Human Lymphocytes In Vitro.

The aim of this in vitro study was to evaluate cytotoxicity and genotoxicity of six different dental nanocomposite materials, three conventional ones and three flowable composite resin materials, in human lymphocytes. The following materials were tested: Tetric EvoCeram, Tetric EvoFlow, Filtek Ultimate, Filtek Ultimate Flow, G-aenial and G-aenial Flo. Cytotoxicity was evaluated for two mass concentrations (0.007 g/mL and 0.013 g/mL) of each material, non-cured and cured, after 4 hours and 24 hours. Genotoxicity was evaluated using micronucleus assay under the same conditions as applied during the investigation of cytotoxicity. Uncured forms of Tetric EvoCeram, Tetric EvoFlow and Filtek Ultimate Flow in higher mass concentration caused genotoxic effect. Uncured G-aenial Flo in higher mass concentration induced apoptosis and necrosis. Uncured Tetric EvoFlow and uncured Filtek Ultimate Flow in higher mass concentration induced early apoptosis after both test periods. None of the conventional composite resin materials tested showed cytotoxicity except for uncured G-aenial, which induced apoptosis in higher mass concentration in both test periods. In conclusion, under the conditions of this in vitro study, cured conventional composites did not show cytotoxic or genotoxic effect, which is important for clinical application of these materials, whereas uncured forms exhibited certain level of cytotoxicity and genotoxicity, mainly because of monomers in their composition.